{
    "description": "Imp extension references valid bidder alias of appnexus defined in the request ext.prebid.aliases field.",
    "mockBidRequest": {
      "id": "some-request-id",
      "site": {
        "page": "test.somepage.com"
      },
      "imp": [
        {
          "id": "my-imp-id",
          "video": {
            "mimes": [
              "video/mp4"
            ]
          },
          "ext": {
            "alias1": {
              "placementId": 12883451
            }
          }
        }
      ],
      "ext": {
        "prebid": {
          "aliases": {
            "alias1": "appnexus"
          }
        }
      }
    },
    "expectedBidResponse": {
      "id":"some-request-id",
      "bidid":"test bid id",
      "cur": "USD",
      "nbr":0,
      "seatbid": [
        {
          "bid": [
            {
              "id": "appnexus-bid",
              "impid": "my-imp-id",
              "price": 0,
              "ext": {
                "origbidcpm": 0,
                "origbidcur": "USD",
                "prebid": {
                  "meta": {
                    "adaptercode": "appnexus"
                  },
                  "type": "banner"
                }
              }
            }
          ],
         "seat": "alias1"
        }
      ]
    },
    "expectedReturnCode": 200
  }